The Evolution of Reproductive Traits in Turtles

In an ongoing study, we are studying the eggs of extinct and modern turtles in order to reconstruct the paleobiology of extinct forms and study the evolution of reproductive traits among turtles. We have described the eggs contained within the body cavity of Adocus and a probable nest of this taxon from the Late Cretaceous of southern Alberta, specimens that represent the first unequivocal associations between fossil turtle skeletal remains and their eggs.

fossilized turtle

Top view of a fossilized turtle, Adocus sp. (TMP 1999.63.2). Roughly one half of carapace is preserved. White circles indicate locations of eggs preserved within the body cavity. Carapace length is 31 cm.

fossilized turtle

Detail of eggs preserved within bodycavity.


Zelenitsky, D.K., Therrien, F., Joyce, W.G., and Brinkman, D. 2008. First fossil gravid turtle provides insight into the evolution of reproductive traits in turtles. Biology Letters. 4: 715-718.

Joyce, W. G. and Zelenitsky, D.K. 2002. Turtle egg pseudomorphs from the Late Jurassic of Schamhaupten, Germany. Archaeopteryx. 20, 57-62.